Impact of intratumoral heterogeneity of breast cancer tissue on quantitative metabolomics using high‐resolution magic angle spinning 1H NMR spectroscopy

High‐resolution magic angle spinning (HR MAS) nuclear magnetic resonance (NMR) spectroscopy is increasingly being used to study metabolite levels in human breast cancer tissue, assessing, for instance, correlations with prognostic factors, survival outcome or therapeutic response. However, the impact of intratumoral heterogeneity on metabolite levels in breast tumor tissue has not been studied comprehensively. More specifically, when biopsy material is analyzed, it remains questionable whether one biopsy is representative of the entire tumor. Therefore, multi‐core sampling (n = 6) of tumor tissue from three patients with breast cancer, followed by lipid (0.9‐ and 1.3‐ppm signals) and metabolite quantification using HR MAS ¹H NMR, was performed, resulting in the quantification of 32 metabolites. The mean relative standard deviation across all metabolites for the six tumor cores sampled from each of the three tumors ranged from 0.48 to 0.74. This was considerably higher when compared with a morphologically more homogeneous tissue type, here represented by murine liver (0.16–0.20). Despite the seemingly high variability observed within the tumor tissue, a random forest classifier trained on the original sample set (training set) was, with one exception, able to correctly predict the tumor identity of an independent series of cores (test set) that were additionally sampled from the same three tumors and analyzed blindly. Moreover, significant differences between the tumors were identified using one‐way analysis of variance (ANOVA), indicating that the intertumoral differences for many metabolites were larger than the intratumoral differences for these three tumors. That intertumoral differences, on average, were larger than intratumoral differences was further supported by the analysis of duplicate tissue cores from 15 additional breast tumors. In summary, despite the observed intratumoral variability, the results of the present study suggest that the analysis of one, or a few, replicates per tumor may be acceptable, and supports the feasibility of performing reliable analyses of patient tissue.     

The small GTPase ADP-Ribosylation Factor 1 mediates the sensitivity of triple negative breast cancer cells to EGFR tyrosine kinase inhibitors

The clinical use of EGFR-targeted therapy, in triple negative breast cancer patients, has been limited by the development of resistance to these drugs. Although activated signaling molecules contribute to this process, the molecular mechanisms remain relatively unknown. We have previously reported that the small GTPase ADP-Ribosylation Factor 1 (ARF1) is highly expressed in invasive breast cancer cells and acts as a molecular switch to activate EGF-mediated responses. In this study, we aimed at defining whether the high expression of ARF1 limits sensitivity of these tumor cells to EGFR inhibitors, such as gefitinib. Here, we show that the knock down of ARF1 expression or activity decreased the dose and latency time required by tyrosine kinase inhibitors to induce cell death. This may be explained by the observation that the depletion of ARF1 suppressed gefitinib-mediated activation of key mediators of survival such as ERK1/2, AKT and Src, while enhancing cascades leading to apoptosis such as the p38MAPK and JNK pathways, modifying the Bax/Bcl2 ratio and cytochrome c release. In addition, inhibiting ARF1 expression and activation also results in an increase in gefitinib-mediated EGFR internalization and degradation further limiting the ability of this receptor to promote its effects. Interestingly, we observed that gefitinib treatment resulted in the enhanced activation of ARF1 by promoting its recruitment to the receptor AXL, an important mediator of EGFR inhibition suggesting that ARF1 may promote its pro-survival effects by coupling to alternative mitogenic receptors in conditions where the EGFR is inhibited. Together our results uncover a new role for ARF1 in mediating the sensitivity to EGFR inhibition and thus suggest that limiting the activation of this GTPase could improve the therapeutic efficacy of EGFR inhibitors.     

Clinical Outcomes of a New Self‐Help Booklet for Premature Ejaculation

IntroductionPremature ejaculation (PE) is quite common. Although effective treatments do exist, only a few affected people consult a practitioner in order to overcome their problem. At the same time, studies have shown that reading didactical documents about their PE problem (bibliotherapy) can be useful to men.AimThe aim of this study was to improve the bibliotherapy approach using up‐to‐date knowledge and techniques. The expected benefits were the following: (i) an effective manual shorter than previous ones; (ii) easier to assimilate therapeutic principles; and (iii) a method thereby made accessible to a broad population most of whom usually do not consult for this type of sexual problem.MethodA short bibliotherapy titled The Practical Guide of PE[in French] was tested among PE subjects who were diagnosed with PE according to Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision criteria. Assessments were made at baseline (N = 421), at 4–8 months (N = 120), and at 10–14 months (N = 79) after they read The Practical Guide. A control group of 66 subjects was left on a waiting list and was assessed 2 months after baseline.Main Outcome MeasuresThe main outcome measures are self‐reported ejaculatory latency time, feeling of control upon ejaculation, sexual satisfaction, distress related to PE, anxiety experienced during sexual intercourse, and sexual cognitions (Sexual Irrationality Questionnaire).ResultsSignificant improvements were found for all the self‐reported parameters, both at 4–8 and at 10–14 months after the bibliotherapy. The improvements were associated with an adjustment of sexual cognitions. The response to treatment seemed better for those subjects with moderate PE. Although the severity criteria used in this study did not precisely meet the International Society for Sexual Medicine criteria for lifelong PE, they were likely related. The response did not seem to be affected by variables such as age, education, or personality.ConclusionIts cost/benefit ratio makes The Practical Guide a valuable therapeutic tool. Kempeneers P, Andrianne R, Bauwens S, Georis I, Pairoux J‐F, and Blairy S. Clinical outcomes of a new self‐help booklet for premature ejaculation. J Sex Med 2012;9:2417–2428.     

Heart remodeling produced by aortic stenosis promotes cardiomyocyte apoptosis mediated by collagen V imbalance

Cardiac remodeling (CR) is a structural change of the heart due to chronic hemodynamic overload related to changes in both myocyte and extracellular matrix (ECM). We investigated that the imbalance of collagen V promotes cardiomyocyte apoptosis that contributes to heart failure and cell death. Aortic stenosis was induced surgically and male Wistar rats were randomized to 18 weeks (Sham 18?w, n?=?12; AoS 18?w, n?=?12) and severe of heart failure (Sham HF, n?=?12; AoS HF, n?=?12) groups. Functional and structural echocardiogram, immunohistochemistry for Ki-67, TUNEL assay and Immunofluorescence for collagen were performed. Our main results were: (1) Progressive reduction of cardiac functional capacity due to cardiac remodeling with decreased eject fraction in heart failure; (2) Imbalance of collagen deposition with increased, crowded and irregular collagen I in situ expression; (3) Dysregulation of dynamic control of collagen fibers with exposed epitopes of collagen V; (4) Additional apoptosis that are dependent to cardiac injury. The collagen V expression in cardiac remodeling is for the first time described and may be related to additional apoptosis and autoimmune response. Our findings suggest a critical role of collagen V in cardiac remodeling to modulate and promote heart failure and death.     

MR‐detectable metabolic consequences of mitogen‐activated protein kinase kinase (MEK) inhibition

Metabolic reprogramming is increasingly being viewed as a hallmark of cancer. Accordingly, metabolic readouts can serve as biomarkers of response to therapy. The goal of this study was to investigate some of the MRS‐detectable metabolic consequences of mitogen‐activated protein kinase kinase (MEK) inhibition. We investigated PC3 prostate cancer, MCF‐7 breast cancer and A375 melanoma cells, and determined that, consistent with previous studies, MRS‐detectable levels of phosphocholine decreased significantly in all cell lines (to 63%, 50% and 18% of the control, respectively) following MEK inhibition with U0126. This effect was mediated by a decrease in the expression of choline kinase α, the enzyme that catalyzes the phosphorylation of choline. In contrast, the impact of MEK inhibition on glycolysis was cell line dependent. A375 cells, which express mutant BRAF, demonstrated significant decreases in glucose uptake (to 36% of control) and lactate production (to 42% of control) in line with positron emission tomography data. In contrast, in PC3 and MCF‐7 cells, increases in glucose uptake (to 198% and 192% of control, respectively) and lactate production (to 177% and 212% of control, respectively) were observed, in line with a previous hyperpolarized ¹³C MRS study. This effect is probably mediated by the activation of the phosphoinositide 3‐kinase pathway and AMP‐activated protein kinase. Our findings demonstrate the value of translatable non‐invasive MRS methods for the provision of information on cellular metabolism as an indication of the activation of potential feedback loops following MEK inhibition. Copyright © 2014 John Wiley & Sons, Ltd.     

Online counseling: An exploratory survey of Italian psychologists’ attitudes towards new ways of interaction†

Objective: Online counseling may be defined as an interaction between users and mental health professionals that takes place through computer mediated communication technology. This study aimed to investigate the attitudes of Italian psychologists towards different aspects of online counseling provided via email, chat, forums, and videoconference. Method: An online questionnaire was administered to a sample of 289 licensed psychologists in the Veneto Region (Italy) in order to collect opinions, preferences, and intentions to use online modalities, along with prior knowledge and practice experiences. Results: Only 18.3% of the respondents had previous experience with online counseling. Overall, the majority of psychologists (62.6%) were favorable towards online counseling, but they also had several reservations about the provision of online diagnosis and therapeutic interventions. Results showed a consistent lack of clarity regarding ethical and penal issues concerning online modalities. Conclusions: More efforts must be directed to deepening the application of new technologies in the field of psychology in order to enable an ethical and professional practice of online counseling in Italy.